docs: def builds(self, confs):
          """For retro compatibility directly assigning builds"""
          self._named_builds = {}
          self._builds = []
          for values in confs:
              if len(values) == 2:
                  self._builds.append(BuildConf(values[0], values[1], {}, {}, self.reference))
              elif len(values) == 4:
                  self._builds.append(BuildConf(values[0], values[1], values[2], values[3],
                                                self.reference))
              elif len(values) != 5:
                  raise Exception("Invalid build configuration, has to be a tuple of "
                                  "(settings, options, env_vars, build_requires, reference)")
              else:
                  self._builds.append(BuildConf(*values))